Internal combustion engine



Sep 27. 32- J M. SHOEMAKER 1,379,551

INTERNAL COMBUSTION ENGINE Filed June 8. 1929 5 Sheets-Sheet 1 GPA VI 7') TANK.

MAIN FUEL TANK.

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3 ulna WIN: 3.

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INTERNAL COMBUSTION ENGINE- Filed June 8. 192 3 Sheets-Sheet 2 1 Snventori l Qftornegs p 1932- I J.M. SHOEMAKER I 1,879,551

INTERNAL COMBUSTION ENGINE Filed June 8, 1929- 3 Sheets-Sheet 3 attorneys Patented Sept. 27, 1932 UNITED; STATES JAMES m. SHOEMAKER, or WASHINGTON, ms'rme'r or COLUMBIA.

INTERNAL COMBUSTIQN. ENGINE.

Application filed June 8,

This invention relates to internal eombus tron eng1nes,,and more particularly to means adapted to facilitate the starting of such engines.

bustion engines, and particularly aeroplane engines, in cold weather presents many difiiculties, and this is primarily due to improper volatilization of the fuel. In order to facilim 1O tate the starting of a cold engine it iscommon practice to greatly enrich the fuel m xture, but this results in excessive wear of cylinders,

pistons, and piston rings, increases fuel consumption, dilutes the lubricating oil, etc.

One of the objects of the present invention is to provide novel means for facilitating the starting of engines, and particularly the starting of engines at low temperatures.

Another object is to provide novel means 29 whereby a cold engine maybe su plied with a properly volatilizedcharge of uel and air during the cranking operation.

A further object is to provide means of the i above character which are adapted to be actuated prior to the starting operation and which do not depend on heat generated by the operation of the engine for their efficiency.

Another object is to provide novel'means for heating the intake manifold of an internal v combustion engine, prior to the startlng of" Another object includes the provision of 0 novel means of the above character which are simple in construction and are adapted to be easily applied to engines now in use. The above and other objects will appear more fully hereinafter.

Several embodiments of the present invention are illustrated, somewhat diagrammatically, in the accompanying drawings, wherein like reference characters refer to likeparts throughout the several views, but it is to be expressly understood that the drawings are The starting ofhigh powered internalcom- 1929; Serial No. 369,459.

for purposes of illustration only, and are not designedasa definition of the limits of the invention, referencebeinghad for this pur pose to the appended claims.

In the drawings:

Fig.1 is a. diagrammatic view illustrating one embodiment of the present invention in combination with the fuel supply system of an aeroplaneengine;

Fig. 2'isla side elevation in section of another-embodiment of the present invention;

Fig. 3' is asectional view taken on the line 3'3. Of Fig.2? 7

Fig; t'isza sectional side view of another structure. embodying the present. invention; m

Fig; 5. is a section taken on the line 5-5 of Fig. 4;

Fig. 6 is adiagrammatic View illustrating an. electrical circuit, which ispreferably employed in, accordance with the present invention and:

Figs; 7; to 9 inclusive, are sectional'side views of other structures embodying the pres-Q ent invention.

Oneform of thepresent invention is shown II) in Fig. 1 in combination with. a fuel supply system foranaeropl'ane engine,.which system includes amain fuel tank 10, a gravity tank: 11, and a carburetor 13 connected-to an intakemanif'oldl l which leads to the engine cylindersl,(not shown). As'is well understood by those skilled'in the 'art,fuel is sup. lied to. car.- buretor 13 from eitherthe main uel tank 10. or gravity tank 11. Flow of fuel from the gravity tank isthrough a pipe 15. controlled by asuitable valve 16.. When the main tank is employed, fuel isdrawn through pipe 17 and strainer 18 by means ofran engine driven pump 19, which is-iprovided with a suitable relief; valve. When the pump operates at a speedsuflicient to develop a pressure in the fuel line to the carburetor in excessof that set on therelief valve, the latteropens and they excess fuel is pumped through line 20. and pipe 151intofthe' gravity tank, the valve 16 being closed. If pump 19 is: inoperative, either'by' reason ofthe enginebeing stopped or through failure of the parts, fuel maybe supplied to the carburetorthrough line 15 by opening valve. 16,.or fromv the main tank by actuating a hand pump 21. When the latter is actuated the fuel passes through a by-pass in pump 19 to the carburetor. Since the above parts are of usual and well known construction and constitute no part per se of the present invention, a detailed description of the construction and operation thereof is unnecessary.-

In order that the charge drawn through the intake into the cylinders during the starting operation may be sufliciently volatilized to insure prompt starting even in the coldest weather, novel means are provided for heating the intake pipe 14 prior to the cranking of the engine. To this end a jacket 22 is provided for the intermediate portion of the intake pipe 14. The diameter of the jacket is such thatan annular heating chamber 22 is formed around the intake, pipe, which chamber is provided with an air inlet'23 and an outlet 24 for burned gases, which latter may, if desired, be led around or through the oil tank 12. A pipe 25, which, in the form shown, is connected to the fuel system intermediate carburetor .13 and pipe 15 provides means for conducting fuel into the chamber 22. Preferably a manually operable plunger pump 26 is interposed in pipe 25, together with a manually operable valve 27, whereby liquid fuel may be forcedthrough a nozzle 28 into the preheater chamber. If desired, a pressure gauge 29 may be connected to pipe 25 at a suitable point, and a two-way valve 30 may also be fitted insaid pipe 25 to permit fuel to be forced by pump 26, whendesired, to a priming outlet 31 for the engine.

' Positioned inthe lower portion of the preheater chamber and insulated therefrom in any suitable manner is a heating coil 32 adapted to be connected by means of a switch 33 to a suitable source of power, such as a battery 34. The battery is also connected by suit-able leads to an indicating device, such as an ammeter 35, and to a suitable thermostat 36 which surrounds intake pipe 14, closely adjacent jacket 22. If considered desirable, screens 37 and 38 may be placed in the exhaust and intake pipes 24 and 23 respectively, to minimize fire" hazards.

In operation switch 33 is closed to supply current to heating coil 32, instrument 35 indicating the flow of current. The circuit through thermostat 36 is normally open when the engine is cold. Valves 16, 27 and 30 are then adjusted and the plunger pump 26 is actuated to spray fuel onto the heating coil 32 where the fuel is ignited. The air for supporting combustion enters through inlet 23 and the products of combustion are exhausted through outlet 24 which'is preferably larger in diameter than the inlet. The burn ing fuel heats the intake pipe and when the temperature of the latter reaches a predetermined point, depending upon the setting of the thermostat 36, the latter is automatically operated to short-circuit coil 32, and the resulting movement of the pointer of indicator 35 informs the operator that the intake pipe has been brought to the desired temperature for starting. Switch 33 may then be opened and the starter (not shown) actuated to crank the engine. As the cold mixture of air and fuel passes through the heated section of the intake pipe said mixture is properly volatilized and the engine is easily started.

In Fig. 2 is shown another embodiment of the invention, wherein the fuel is sprayed into an annular chamber through a coil pipe 39 which is positioned in the lower part of the chamber surrounding intake pipe 14, suitable openings 40 being, provided in the upper portion of pipe 37 for this purpose. A spark plug 41 is secured to the jacket 22 in a position to ignite the fuel issuing from open-- ings 40 in pipe 39, current for said plug being provided by magneto or other suitable means (not shown) through leads 42. A plan view of the coil pipe and spark plug of Fig. 2 is shown in Fig. 3.

In Fig. 4 there is shown another embodiment of the invention wherein the jacket 43 which surrounds the intake pipe is substantially spherical in shape, and that portion of the intake pipe within the acket is provided with fins 44 to more efficiently carry out the heating action. v

In Figs. 5 and 6 there is shown one type of thermostat which maybe employed in accordance with'the present invention. As illustrated, the device comprises a curved thermostatic element 45, which closely surrounds intake pipe 14 and is secured to a casing 46,

which surrounds said intake pipe, the connection between the element 45 and casing 46 being shown at 47 with the thermostatic element insulated from the casing in any suitable manner. The free end of element 45 terminates closely adjacent a terminal 48 that extends through the wall of casing 46. The air gap between terminal 48 and element 45 may be adjusted, if desired, as by means of a threaded member 49 which is mounted in the wall of casing 46 and is adapted to engage the thermostatic element 45 intermediate its ends. The increase in temperature of the intake pipe which is transmitted to the thermostatic element 45 causes the latter to eX- pand into engagement with the contact 48,

running, the exhaust manifold of the engine being diagrammatically shown at 52.

In Fig. 8 there is shown another embodiment of the present invention wherein the air for supporting combustiion within the jacket 53 of the preheater is introduced through an annular opening 54 which surrounds the intake pipe 14 closely adjacent the bottom of the preheater chamber. The air inlet member 55 extends upwardly beyond the bottom of the jacket 53 as at 56 to provide the necessary receptacle for holding the fuel introduced through nozzle member 28.

In Fig. 9 there is illustrated still another embodiment of the present invention wherein a heating coil 57, which is substantially vertically disposed within the jacket 58, is provided for igniting the fuel shown at 59. By this arrangement the ignition of the fuel proceeds from the upper surface thereof, the coil insuring that all fuel introduced into the preheater chamber will be burned.

It will be understood that the jacket for forming the annular chamber around the intake pipe may assume various shapes and forms and need not be made integrally with the intake pipe as illustrated. By making said acket in readily attachable and removable sections the installation on en ines now in use may be facilitated. It will be readily understood by those skilled in the art that thermostaticdevices other than the one illustrated may be employed to indicate to the operator when the temperature of the intake pipe has been brought to the desired point.

The use of the apparatus greatly facilitates the starting of cold engines and overcomes the objectionable features pointed out above that have been present in devices of this character heretofore employed. The fuel drawn into the engine cylinders is not weakened by burned gases from the preheater and the latter, if desired, may be conducted by or through the lubricating oil tank 12 as shown in Fig. 1 to raise the temperature of the oil therein. Various changes may be made in the details of construction and arrangement of the parts and reference will therefore be had to the appended claims for the definition of the limits of the invention.

What is claimed is:

1. A device for heating the intake pipe of an internal combustion engine, prior to and after the starting of the engine, including a jacket surrounding a portion of the intake pipe and forming with the latter two annular chambers, means for introducing fuel into one of said chambers and for igniting said fuel therein, means operatively associated with said igniting means for indicating when the intake pipe has been raised to a predetermined temperature, and means for conducting exhaust gases from the engine through the other of said chambers.

2. A device for heating the intake pipe of an internal combustion engine, comprising a jacket surrounding a portion of said pipe and forming therewith a pair of annular chambers, means for introducing liquid fuel into one of said chambers, including a nozzle and manually operable means for forcing fuel through said nozzle, means for igniting the fuel introduced into said chamber, means for JAMES M. SHOEMAKER. 

